Saturday, December 3, 2022


How to replace the window in an RV door


By Russ and Tiña De Maris

If the window frame in your RV’s entry door is beginning to look a little frayed around the edges (UV light can chew them up), or you need to replace your entry door glass, you may be puzzled about how to proceed. The job isn’t all that difficult, but there are a couple of tricks that can make it much easier. We’ll clear up some of the mystery.

Entry door window frames are a two-piece design. You’d think to replace the frame you’d just go down and buy a “pair” of frame pieces. Here’s one of the RV manufacturing world’s great mysteries. The frames are sold as halves, either an exterior half for the outside of the door, or the interior half. But you’ll probably find a dire warning printed on the packaging: “It is strongly recommended that both interior and exterior frames be replaced at the same time.”

The “duh” question then becomes, “Why not sell both halves at a reasonable price, together in one package?” And what’s the big deal, anyway? Our job was to replace a weather-cracked exterior frame half, and cheapskates that we are, we simply bought the exterior half because the interior side looked good enough to us. We later found out one possible flaw in the reasoning.

window1-759If your door glass needs replacement, don’t immediately run to the big box hardware store looking for a replacement. The original glass is tempered—for a good reason. When broken, non-tempered glass has a nasty way of shattering into long, deadly, sharp shards. When replacing glass in an RV, the code calls for tempered glass which, when broken, typically chunks into smallish, rounded pieces, far less likely to cause great bodily harm.

Your local glass shop can probably sell you tempered glass, but it may require a few days from order to readiness. Tempering requires cooking the cut-to-size glass in an oven, and many shops have to send out the glass for the tempering process. Yes, you could replace your door glass with acrylic, but don’t use inexpensive Plexiglas. Plexi is easy to work with, but it gets brittle at low temperatures and breaks easily. Lexan, although more expensive, is your best alternative.

Before you fire off an order for tempered glass through a glass outfit, check with local RV parts dealers. Many keep replacement glass in stock, and their price and availability may shine in comparison. Or, if you know you have a change-out job coming up, look on Amazon — you may find sellers that will equip you with a complete two-piece frame and glass for far less than you’d imagine.

It’s really best to have a helper when removing and replacing a door glass unit. The actual glass is not directly attached to the window frame, and you’ll find yourself juggling three pieces — one of them breakable.

window2-759Removing the existing unit is best accomplished with a cordless drill equipped with a #2 Phillips screw bit. There are 12 screws that hold the frames together. Zip out the screws, and have your helper ready to stabilize the whole shooting match. If by some chance the sealant on the exterior frame is still intact, remove the interior frame and glass from the inside of the door. In our case, all the pieces came falling away merrily — and happily, the glass was caught on the way to the ground.

With the frame removed, clean up any frame piece you’ll be reusing. A flat scraper and at times a rag with solvent are about all you’ll need. If the glass is intact, use a scraper to remove the sealant and clean the glass with glass cleaner.

Butyl putty tape on glass perimeter gets sealant. Life’s a lot easier with a bench or table to complete your prep work. Lay the exterior frame on the bench with the “outside” down. You’ll need to lay a layer of butyl putty tape around the far outside perimeter of the window frame. We found that by covering about half of the surface of the frame with putty tape then coming back and cutting off the excess (the tape is much wider than the frame’s flange) we could then use the cut off piece to complete the “puttying” of the frame.

Next, specifications call for silicone sealant to be used to form a complete bead around the interior perimeter of the exterior door frame. This is the bed that the door glass will seat into, and keep the rain from coming in around the glass. We opted to go with a non-standard approach and use an acrylic sealant instead. We hate the “nothing will ever stick to silicone” issue, and if we need to reseat the glass in the future, prep work will be much faster.

Here’s an installation trick: If you have time to wait, put down the bead of sealant and lay the glass in place. Leave putting on the perimeter of putty tape until AFTER the other sealant has set up and now firmly holds the glass to the frame. This will make handling the glass and frames oh so much easier. Since we were living in the trailer when we had to replace our glass, we didn’t have that luxury, and manipulating two frames and a chunk of glass — all nicely wet with sticky sealant — was like a page from the Laurel and Hardy playbook.

With plenty of help, bring the exterior frame and its glass companion around and shove them in the open hole of the door. By the way, the exterior frame HAS NO SCREW HOLES in it. The screws go in from the interior frame ONLY.

The new window frame is now in place. Now align the interior door frame with the exterior frame. Here’s where buying both of these guys new may make a difference. There was a slight bit of warping in our old interior frame, which made alignment a bit tricky. Like any good follower of the “Red Green Show” we said, “What the heck?” and grabbed screws that were just a bit longer than the originals. After all, that little bit of extra length made alignment so much easier. The first screw put in practically nicked the helper’s hand on the far side of the door — the screws you take out are precisely the correct length. Snug the screws down tight enough to squish out some of the putty tape, but don’t overdo it.

If your installation is anything like ours, now is NOT Miller Time. The hash job we made with not having enough hands to juggle fresh glass adhesive and the addition of plenty of putty tape spillover meant an extra 20 minutes spent rubbing off “goofs,” in addition to using the scraper to remove the excess putty tape.

Despite the hassles, the new window frame is a big improvement over its predecessor.

##rvt759 #RVDT1219

Did you enjoy this article?

Click on a star to rate it!

Average rating 0 / 5. Vote count: 0

No votes so far! Be the first to rate this post.


Notify of

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Inline Feedbacks
View all comments
2 years ago

Our Cedar C fifth has no windows beside our door. In December before heading south I replaced the obscured glass with dark clear tinted glass. Painted the frame. Now it matches the rest of the windows and we can now see who’s at the door.
One of the best changes to our trailer.

6 years ago

I have a new one of these white frames in my Chinook/Ford rv door. Imho one can push the glass enough to violate the frame easily. I would like to replace my 12×21 (w/o verifying) w an alum screw together frame ; inner clamp ring. I’ve seen 12×24 but never 12×21.
Russ & Tina I’ve enjoyed your work over the years, great travels!

Loren Clark
6 years ago

Where do we go to get these frames as I would like to add a lower window in my door to allow me to see cars in my blind spot!

Russ and Tiña De Maris(@russ)
6 years ago
Reply to  Loren Clark


You can find a frame kit for a door window at many RV part supply places. Typically the kit includes both the inner and outer frame; you may need to supply your own sealant — I recommend butyl tape.

Subscribe to our newsletter

Every Saturday and Sunday morning. Serving RVers for more than 20 years.